Why would he not text back but always tries to be around me at work?

so basically more often than not he doesn't text back though when we are at work he stares at me, tries to be around my work station. and tries to get attention from me.

what gives?

also he admitted having feelings for me (even though he finally told me he has a gf) while we worked together for 2 weeks and now he says "i was just being nice" though a lot of his actions showed jealousy, protectiveness and things beyond just being "nice".